Lifting and carrying clamp for handling stone slabs



L 0 S 7 W 7 RR n e mom 3 7, Nc l70 6 s |||I| I l l I l I l I I l l ||IJE 9m, B VW T A NH A a I IK E m PIM. f m s F V l l l l l l l I l l I nlmTmf G .N I L m N o L 5 m m R m m 8 P o www c. m d 1 S 6 Kfm n T Y F m v,C Q m A [.II G .lx1 w m W 88 3 m L 1 8, 2 M m m g .n F p A Patented Apr.28,` 1953 LIFTING AND CARRYING CLAMP FOR HANDLING STONE SLABS Ted KeithCornwell, Cold Spring, Minn., assignor to Cold Spring Granite Company,Cold Spring, Minn., a corporation of Minnesota Application December 8,1950, `Serial N o. 199,856

1 Claim.l (Cl. 294-103) This invention relates to a lifting and carryingclamp for handling stone slabs.

It has been a considerable problem in erecting and handling large stoneslabs such as marble for stone veneering and the like to provideefflcient means for securely holding the gripping apparatus on the slabwithout damaging the highly polished surface or causing breakage of theslab and while permitting the slab to be lowered and placed directlyinto the desired position whilestill being supported from a iieXibleoverhead supporting element.

It is an object of my invention to provide a slab lifting and erectinggripping clamp particularly adapted for use with highly polishedhard-surfaced stone slabs and adapted to be supported from an overheadflexible hoist element and to be lowered thereby into the desiredposition.

It is another object to provide a slab-erecting clamp particularlyadapted for use with highly polished hard-surfaced stone slabs andhaving a clamping jaw element with a slightly compressiblestone-engaging surface fixed thereto and underlying a reinforcingpressure-applying element to equally distribute the clamping pressureover the relatively soft gripping surface.

More specifically, it is an object to provide a gripping clamp having aconnector element adapted to be attached to a iiexible overheadsupporting member and having a stationary gripping element forengagement in a cooperating recess or slot provided in the rearunpolished side of a stone slab and a clamping jaw element having areinforcing pressure-applying outer member with a slightly compressiblepolished surface-engaging gripping element underlying saidpressure-applying element and producing sufcient friction against saidhighly polished surface to permit suspension of the slab solely by meansof the gripping clamp alone to facilitate erection of the slab.

It is the combination of a shiftable, relatively large area gripping jawhaving a rigid pressureapplying backing member with an underlying,slightly compressible gripping surface fixed thereto with a clamp havingan upstanding attachment element for connection with an overheadfiexible supporting member which permits a stone slab such as granite ormarble to be tightly gripped along only the top marginal edge portionwhich facilitates the handling and erection thereof.

The above and other objects and advantages of the invention will morefully appear from the following description made in connection with theaccompanying drawings, wherein like reference characters refer to thesame or similar parts throughout the several views, and in which:

Fig. 1 is a perspective View of my new gripping clamp in full linesshowing a stone slab gripped thereby and supported for erection be ingshown in dotted lines;

Fig. 2 is a transverse vertical sectional View showing a stone slabsecurely gripped between the jaws of my gripping clamp with the over-thead support member `connected therewith.

As illustrated in the accompanying drawings, a gripping clamp, which inthe form shown has a rigid, inverted, substantially U-shaped body '5, isprovided, having` the rear arm 5a and the front arm 5b rigidlyinterconnected by the supporting element 5c. A stationary gripping jawhaving the diminished` projection 6 is fixed to the rear arm 5a and isadapted to engage the rear side of a slab such as the rear unpolishedside of a slab T. The slab has a recess or slot formed in the rearsurface of the upper marginal edge portion and the diminished projection6 of the stationary gripping jaw is constructed t0 be received in saidrecess.

A shiftable clamping jaw 8 is mounted on an elongated shiftable shanksuch as the threaded shank 9 which is threadably received. through thefront arm 5b as best shown in the accompanying drawings. The clampingjaw 8 is laminated with two layers being formed thereon. An outerpressure-applying layer in the shape of a disc 8a which is made from anysuitable rigid material such as steel, wrought iron, or the like ofsufiicient thickness to uniformly distribute the pressure applied byturning the screw shank 9 through the arm 5b. A relatively soft.slightly compressible lamination 8b is fixed under disc 8a and issubstantially co-extensive therewith to engage the highly polished frontsurface of the slab l. A relatively soft metallic material is preferablyused for this lamination 8b such as lead or Babbitt material. Thebacking pressure applying element permits a suiiicient surface area ofrelatively soft gripping material to be provided to prevent injury tothe slab surface and to prevent possible cracking of the slab whengripping pressure is applied thereto.

An attachment ring I0 is connected to the supporting element 5c and isadapted to receive a hook ll carried by a depending flexible supportingmember such as the chain I2 which is, of course, connected with anysuitable hoisting means such as a conventional block and tackle (notshown).

After long experimentation with the proper material to use for theengaging surface of the movable jaw, I found that a soft metallicmaterial such as lead produced surprisingly .satisfactory results. 'isthe 'slightly compressible f'quality of this surface-engaging jaw thatgives it its high frictional resistance without damaging the highlypolished surface or causing possible cracks in the veneered slab. v y

It Will be seen that I have provided f'a 'relatively simple yet highlyefficient lifting and vcarrying clamp for gripping stone slabs toAfacilitate han* dling and erection thereof. 4My clamp is provided Withan attachment element adapted to be quickly and easily attachedt'o ahook suspended from an overhead hoisting mechanism and to be supportedsolely thereby. The general 'combination of the reinforcing backingelement with a slightly compre's'sible 'gripping ysurface xed theretoand means ior tightlyclamping 'said compressible surface yagainst thehighly polished iront surface of a 'stone slab 'produces a clamp whichis adapted to tightly grip and hold a 'stone cuter jaw being providedwith a slightly eompressible metallic lgripping surface having areinforcing `rigid backing element 'xed therebehind to permit securegripping `of a highly polished stone "surface produces a lifting clampadapted to greatly facilitate handling Vand erection of stone slabs andmaterially Aspeeds up erection time, since the slab is suspended solelyfrom the medial upperl marginal edge `portion thereof and permits thesides and bottom edges to `be precisely positioned relative to the otherslabs before the slab being erected is released 'from its overheadsupport. The rear stationary 'jaw `fi is relatively small to permitreception thereof in a 'recess or slot formed in the rear surface of theupper marginal edge `portion of the slab.

` it will, of course, be understood that various changes may be made "inthe form, details, arrangement and proportions of the various parts 4without departure from the scope of my present invention, which,generally stated, consists in the matter shown, and described, and setforth in the appended claim.

What I claim is:

.A lifting and carrying clamp adapted for use in 'handling Fand erectingstone veneering slabs 'for buildings and the Elike having one polishedsurface on the outer side thereof, said clamp 'comprising a rigidunyielding body member, a relatively thin stationary jaw fixed independing relation at'the rear end portion of said body and having anoutwardly projecting interlocking element ad'apte'd't intert with acooperating recess formed .in the back side of the slab, a shiftableclamping javv mounted at the outer portion of sai-d body and disposed inopposed relation to said xed clamping jaw and forming the outer frontjaw member of the gripping clamp, an unyielding pressure-applyingbacking vplate on the outer front jaw member vvith a 'slightlyVcompressible relatively soft metallic layer fixed on the backing platefor vclamping engagement against the 'smooth polished `outer slabsurface, means mounting said .shiftablecla-inping jaw on said body withprovision for forcibly projectingv said front jaw member toward the rearjaw member to tightly vclamp said two jaws against the respective frontand rear sides of the upper marginal 'portion of a stone slab to formthe sole Vconnection therewith and tightly hold the rear outwardlyprojecting interlocking element in intertting relation within thecooperating recess in the back side of 'the slab, and an attachmentelement mounted on an intermediate portion of said body member".

TED KEITH CORNVELL.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 291,248 West Jan. 1, 1884 307,453 Galbraith NOV. 4, 1884'387,109 Sanford July 31, v1888 855,989 Sh'el" t al June 4, 1907 865,444'staie'y' sept. in, 1907 1,221,400 Wilhelm et al. Apr. 3, 1917 1,535,022Jenkins i.. Apr. 2l, 1925 FOREIGN PATENTS Number n Country Date 13,305Norway Feb. 6, 1905

